(HEDS-9x00) Two Channel High Resolution Optical Incremental Encoder Modules

www.DataSheet4U.com Two Channel High Resolution Optical Incremental Encoder Modules Technical Data HEDS-9000/9100/9200 Extended Resolution Series Features • High Resolution: Up to 2048 Cycles per Revolution • Up to 8192 Counts per Revolution with 4X Decoding • Two Channel Quadrature Output • Low Cost • Easy to Mount • No Signal Adjustment Required • Small Size • -40°C to 100 °C Operating Temperature • TTL Compatible • Single 5 V Supply codestrip, these modules detect relative linear position. These modules consist of a lensed Light Emitting Diode (LED) source and detector IC enclosed in a small C shaped plastic package. Due to a highly collimated light source and unique photodetector array, these modules provide a highly reliable quadrature output. The HEDS-9000 and HEDS-9100 are designed for use with codewheels which have an optical radius of 23.36 mm and 11 mm respectively. The HEDS-9200 is designed for use with a linear codestrip. These components produce a two channel quadrature output which can be accessed through five 0.025 inch square pins located on 0.1 inch centers. The resolution of the HEDS-9000 Options T and U are 2000 and 2048 counts per revolution respectively. The HEDS-9100 Options B and J are 1000 and 1024 counts per revolution respectively. The HEDS-9200 Option 300 and 360 linear encoder modules have resolutions of 300 and 360 lines per inch. Consult local Agilent sales representatives for other resolutions. Note: Agilent Technologies encoders are not recommended for use in safety critical applications. Eg. ABS braking systems, power steering, life support systems and critical care medical equipment. Please contact sales representative if more clarification is needed. Description The HEDS-9000 Options T and U and the HEDS-9100 Options B and J are high resolution two channel rotary incremental encoder modules. These options are an extension of our popular HEDS-9000 and HEDS-9100 series. When used with a codewheel, these modules detect relative rotary position. The HEDS-9200 Option 300 and 360 are high resolution linear encoder modules. When used with a ESD WARNING: NORMAL HANDLING PRECAUTIONS SHOULD BE TAKEN TO AVOID STATIC DISCHARGE. 2 Block Diagram Output Waveforms Theory of Operation The diagram shown on the following page is a block diagram of the encoder module. As seen in this block diagram, the module contains a single LED as its light source. The light is collimated into a parallel beam by means of a single polycarbonate lens located directly over the LED. Opposite the emitter is the integrated detector circuit. This IC consists of multiple sets of photodetectors and the signal processing circuitry necessary to produce the digital waveforms. The codewheel/codestrip passes between the emitter and detector, causing the light beam to be interrupted by the pattern of spaces and bars on the codewheel. The photodiodes which detect these interruptions are arranged in a pattern that corresponds to the codewheel/ codestrip. These detectors are also spaced such that a light period on one pair of detectors corresponds to a dark period on the adjacent pair of detectors. The photodiode outputs are then fed through the signal processing circuitry resulting in A, A, B, and B. Comparators receive these signals and produce the final outputs for channels A and B. Due to this integrated phasing technique, the digital output of channel A is in quadrature with that of channel B (90 degrees out of phase). transition in the output of channel A and the neighboring transition in the output of channel B. There are 4 states per cycle, each nominally 90°e. State Width Error (∆ S): The deviation, in electrical degrees, of each state width from its ideal value of 90°e. Phase (φ ): The number of electrical degrees between the center of the high state of channel A and the center of the high state of channel B. This value is nominally 90°e for quadrature output. Phase Error (∆φ ): The deviation of the phase from its ideal value of 90°e. Direction of Rotation: When the codewheel rotates in the direction of the arrow on top of the module, channel A will lead channel B. If the codewheel rotates in the opposite direction, channel B will lead channel A. Optical Radius (Rop ): The distance from the codewheel’s center of rotation to the optical center (O.C.) of the encoder module. Definitions Count (N): The number of bar and window pairs or counts per revolution (CPR) of the codewheel. 1 cycle (C): 360 electrical degrees (°e), 1 bar and window pair. 1 Shaft Rotation: 360 mechanical degrees, N cycles. Pulse Width (P): The number of electrical degrees that an output is high during 1 cycle. This value is nominally 180°e or 1/2 cycle. Pulse Width Error (∆ P): The deviation, in electrical degrees of the pulse width from its ideal value of 180°e. State Width (S): The number of electrical degrees between a 3 Package Dimensions 26.67 (1.05) 15.2 (0.60) 2.54 (0.100) TYP. 1.52 (0.060) 1.0 (0.04) DATE CODE 3.73 ± 0.05 (0.147 ± 0.002) 1.02 ± 0.10 (0.040 ± 0.004) HEDS-9X00 YYXX X00 8.6 (0.34) CH. B VCC CH. A N.C. GND 5 4 3 2 1 OPTION CODE 5.1 (0.20) 1.8 (0.07) 2.21 (0.087) 2.54 (0.100) 2.9 (0.11) 6.9 (0.27) GND VCC 0.63 (0.025) SQR. TYP. 20.8 (0.82) 11.7 (0.46) 11.9 (0.47) ALIGNING RECESS 2.44/2.41 DIA. 1.85 (0.073) (0.096/0.095) 2.16 (0.085) 8.64 (0.340) DEEP REF. C L 17.27 (0.680) 20.96 (0.825) 2.67 (0.105) DIA. MOUNTING THRU HOLE 2 PLACES 2.44/2.41 X 2.79 (0.096/0.095 X 0.110) 2.16 (0.085) DEEP OPTICAL CENTER 1.78 ± 0.10 (0.070 ± 0.004) 2.92 ± 0.10 (0.115 ± 0.004) 10.16 (0.400) OPTICAL CENTER LINE 5.46 ± 0.10 (0.215 ± 0.004) 4.75 ± 0.10 (0.187 ± 0.004) ALIGNING RECESS 2.44/2.41 X 2.79 (0.096/0.095 X 0.110) 2.16 (0.085) DEEP OPTICAL CENTER 8.81 5.8 45° (0.23) (0.347) ALIGNING RECESS 2.44/2.41 DIA. (0.096/0.095) 2.16 (0.085) DEEP 4.11 (0.162) 6.35 (0.250) REF. SIDE A TYPICAL DIMENSIONS IN MILLIMETERS AND (INCHES) SIDE B Absolute Maximum Ratings Storage Temperature, TS ..................................................................... -40°C to 100°C Operating Temperature, TA ................................................................ -40°C to 100°C Supply Voltage, VCC ...................................................................................... -0.5 V to 7 V Output Voltage, VO ........................................................................................ -0.5 V to VCC Output Current per Channel, Iout ................................................. -1.0 mA to 5 mA Recommended Operating Conditions Parameter Temperature Supply Voltage Load Capacitance Count Frequency Shaft Axial Play Symbol TA VCC CL f Min. -40 4.5 5.0 Typ. Max. 100 5.5 100 100 ± 0.125 ± 0.005 Units °C Volts pF kHz mm in. Ripple < 100 mV p-p 3.3 kΩ pull-up resistor Velocity (rpm) x N/60 Notes Note: The module performance is guaranteed to 100 kHz but can operate at higher frequencies. For frequencies above 100 kHz it is recommended that the load capacitance not exceed 25 pF and the pull up resistance not exceed 3.3 kΩ. For typical module performance above 100 kHz please see derating curves. 4 Electrical Characteristics Electrical Characteristics over Recommended Operating Range, typical at 25°C. Parameter Supply Current High Level Output Voltage Low Level Output Voltage Rise Time Fall Time Symbol ICC VOH VOL tr tf 180 40 Min. 30 2.4 0.4 Typical 57 Max. 85 Units mA Volts Volts ns ns IOH = -200 µA max. IOL = 3.86 mA CL = 25 pF RL = 3.3 kΩ pull-up Notes Encoding Characteristics Encoding Characteristics over Recommended Operating Range and Recommended Mounting Tolerances. These Characteristics do not include codewheel/codestrip contribution. The Typical Values are averages over the full rotation of the codewheel. For operation above 100 kHz, see frequency derating curves. Description Pulse Width Error Logic State Width Error Phase Error Symbol ∆P ∆S ∆φ Typical 5 3 2 Maximum 45 45 15 Units °e °e °e Note: Module mounted on tolerance circle of ± 0.13 mm (± 0.005 in.) radius referenced from module Side A aligning recess centers. 3.3 kΩ pull-up resistors used on all encoder module outputs. 5 Derating Curves over Extended Operating Frequencies (HEDS-9000/9100/9200 Extended Series) Below are the derating curves for state, duty, phase and VOH over extended operating frequencies of up to 240 kHz (recommended maximum frequency is 100 kHz). The curves were derived using standard TTL load. –40°C operation is not feasible above 160 kHz because VOH will drop below 2.4 V (the minmum TTL for logic state high) beyond that frequency. CHANGE IN PULSE WIDTH ERROR (ELECTRICAL DEGREE) CHANGE IN STATE WIDTH ERROR (ELECTRICAL DEGREE) 0 50 -10 100°C -20 25°C 40 -40°C 30 25°C -30 -40°C -40 20 100°C 10 -50 120 140 160 180 200 220 240 0 120 140 160 180 200 220 240 FREQUENCY (kHz) FREQUENCY (kHz) 0 CHANGE IN PHASE ERROR (ELECTRICAL DEGREE) CHANGE IN VOH (VOLTS) 5 4 100°C 25°C 2 -40°C -5 100°C 25°C -10 -40°C 3 1 0 120 120 140 160 180 200 220 240 140 160 180 200 220 240 FREQUENCY (kHz) FREQUENCY (kHz) 6 Gap Setting for Rotary and Linear Modules Gap is the distance between the image side of the codewheel and the detector surface of the module. This gap dimension must always be met and codewheel warp and shaft end play must stay within this range. This dimension is shown in Figure 1. SIDE B +0.51 +0.020 6.63 -0.25 0.261 -0.010 NOTE 1 ( ) SIDE A IMAGE SIDE OF CODEWHEEL/CODESTRIP CODEWHEEL/CODESTRIP +0.25 +0.010 3.56 -0.51 0.140 -0.020 NOTE 1 ( ) Mounting Considerations for Rotary Modules Figure 2 shows a mounting tolerance requirement for proper operation of the high resolution rotary encoder modules. The Aligning Recess Centers must be located within a tolerance circle of 0.13 mm (0.005 in.) radius from the nominal locations. This tolerance must be maintained whether the module is mo